Therapeutic compounds



United States Patent '0 THERAPEUTIC COMPOUNDS Arthur W. Weston, Wankegan, 11]., assignor to Abbott Laboratories, North Chicago, Ill., a corporation of Illinois No Drawing. Application June 28, 1952, Serial No. 296,238

7 Claims. (Cl. 260247.2)

This invention relates generally to novel physiological active substances and more specifically to derivatives of arylcycloalkane carboxylic acids which are useful therapeutically as antispasmodics. (Substances which'have a relaxing effect on smooth muscle.)

This application is a continuation-in-part of my copending application S. N. 600,241 filed June 18, 1945, now abandoned.

The novel compounds to which this invention pertains are selected from members of the group consisting of an ester of the formula the acid addition salts thereof and the quaternary ammonium salts thereof, wherein m is an integer from 2-5 inclusive, R1 is 0, R2 is a lower alkylene group and NR3 is a monocyclic, heterocyclic, nitrogen containing group.

The monocyclic, heterocyclic, nitrogen containing group referred to herein includes the morpholine, piperidyl and pyrollidyl groups as well as other less commonly known members of this class.

The term lower alkylene group as used herein to define the symbol R2 is intended to include the CH2, C2H4, CsHe, C4Hs, CsHio, CsHm and similar radicals and the branched chain equivalents thereof.

These compounds have been found to have valuable therapeutic properties, especially as antispasmodic agents. They may be administered orally or parenterally. For oral use, they may be prepared in liquid form, or in solid form as powder or tablets, either alone or in admixture with other substances. Usually these substances are more soluble in water when in the form of acid addition salts rather than as the free bases. Any acid which produces a water-soluble salt and does not appreciably enhance the toxicity is suitable for use in forming the salts. Such acids as sulphuric, phosphoric, hydrochloric, levulinic, mucic, acetic and tartaric acid are among those which are satisfactory. The salts produced by combination of these bases with certain other non-toxic acids such as tannic acid are very sparingly soluble in water. These sparingly soluble compounds, as well as the free bases, may be administered when the pharmacological elfect desired should be slow in onset and relatively long in duration. Where any ester or amide is mentioned in the following product claims, it is intended to include both the free base and the salts. It will be obvious that such addition compounds as the quaternary ammonium salts, of which the methiodide of Example is an illustration, may be derived from any of the other examples of esters or amides and by use of other organic halides or sulfates.

The compounds included in this invention may be prepared according to the specific instructions given in the hereinafter presented examples and by numerous other methods. For instance the l-arylcycloalkane-l-carboxylic acid is neutralized with an alcoholic solution of an alkali metal hydroxide (such as the hydroxide of sodium or potassium). The mixture is concentrated to dryness and then heated with the appropriate aminoalkyl halide. The resulting mixture is Washed with water, concentrated, dried, and distilled (under reduced pressure, if necessary). Or if there is used an organic halide containing two halogen atoms per molecule and only one has reacted with the alkali metal salt then the monohalogen compound is allowed to react with the appropriate substance (such as an alkyl amine) to replace the remaining halogen atom by the desired group. The reaction may be carried out by heating for several hours in an organic solvent such as benzene. The mixture is then washed with water, dried, concentrated and purified by distillation (under reduced pressure, if necessary).

The esters may also be produced as follows: The l-aryll-cycloalkane carboxylic acid halide is heated with the desired halogen substituted alcohol to produce a haloalkyl ester. This ester is then heated with the desired amine with or without the addition of solvent. The resulting amino ester of the l-aryl-cycloalkane-l-carboxylic acid may be purified as above.

Compounds such as those produced by the above general methods are converted to acid addition salts by dissolving them in an organic solvent such as ether and adding the desired acidic material such as a dry hydrogen chloride gas or concentrated sulphuric acid. The salt precipitates and is then filtered oil and dried. It is further purified by recrystallization from organic solvents.

Quaternary ammonium salts are produced by treating the bases such as those formed in methods outlined above with the appropriate organic halide or sulfate. This is done by mixing the two reactants with or without the use of a diluent such as an organic solvent. The crude product is recrystallized from organic solvents.

Tov produce the salts of the esters previously described the appropriate l-aryl-l-cycloalkane carboxylic acid is heated with the appropriate dialkyl aminoalkyl halide, in presence of a solvent such as isopropyl alcohol, dioxane, etc.

Instead of the starting materials mentioned in the preceding sentence there may be substituted a salt of the l-aryl-l-cycloalkane carboxylic acid and a salt of the alkyl aminoalkyl halide.

The invention is disclosed in further detail bythe following examples which are provided solely for the purpose of illustrating the invention and which are intended in no way to be construed as limiting it in spirit or in scope. Relative amounts of materials are given in parts by weight unless otherwise indicated.

A mixture of 20.4 parts of 1-phenylcyclohexane-l-carboxylic acid and 30 parts of thionyl chloride is converted into the acid chloride by heating on a steam bath for four hours. The acid chloride is dissolved in cc. of chloroform, treated with 34.6 parts of v-morpholino-Bfidimethyl propyl alcohol, then stirred and refluxed several hours. The reaction mixture is washed first with dilute sodium hydroxide, then with water and finally dried, concentrated, and distilled. The *y-morpholino-BJS-dimethylpropyl 1-phenylcyclohexane-1-carboxylate thus obtained amounts to 31.7 parts or 88% of theory. It

solidifies and after crystallizing from dilute alcohol melts at 54-55 C.

EXAMPLE 1B The hydrochloride formed by treating the base de scribed in Example 1A with hydrogen chloride in a suitable solvent can be crystallized from acetone. It melts at ISO-181 C.

EXAMPLE 1C The methiodide of the base mentioned in Example 1A is prepared by allowing the base to react with methyl iodide at room temperature. The-quaternary ammonium salt of the base is obtained and is crystallized from an absolute alcohol-ether mixture.

EXAMPLE 2A w-Morpholinohexyl 1 -phenylcyclohexane-1 -carboxylate Clix-Cg:

H30 OH:

H; HI

1-phenylcyclohexane-l-carboxylic acid chloride, prepared from 22.1 parts of the corresponding acid and 3 parts of thionyl chloride, is treated with 34.3 parts of w-morpholino-N-hexanol and the reaction product isolated as described in Example 1A. The w-morpholinohexyl l-phenylcyclohexane-l-carboxylate is thus obtained in an 87% yield. It boils at 22823l C. at 4 mm. and has a 1.5155.

This base may also be prepared by an alternate method as follows:

87.7 parts of the above acid is neutralized with an alcoholic solution of potassium hydroxide. The potassium salt obtained by concentrating the resulting solution is dried and then heated at 100 C. for 18 hours with excess hexamethylene dibromide. The reaction mixture is washed with water, concentrated, dried and distilled. The w-bromohexyl l-phenylcyclohexane-l-carboxylate thereby produced amounts to 126 parts or 80% of theory. It boils at 204-205 C. at 4 mm. and has 11.3 1.5284.

A solution of 123.5 parts of this bromohexyl ester and 59.0 parts of morpholine in 200 parts of benzene is refluxed and stirred for 5.5 hours. After washing with water, the benzene layer is concentrated, dried, and distilled whereby 108 parts or an 80% yield of the w-morpholinohexyl 1-phenylcyclohexane-l-carboxylate, boiling point, 228-229 C. at 3 mm., n 1.5165 is obtained.

EXAMPLE 2B The hydrochloride prepared in the usual manner from the base described in Example 2A melts at 121-123 C. after crystallization from ethyl acetate.

EXAMPLE 3 'y-Morpholinopropyl 1 -phenyIcycl0hexane-1-carboxylate 10.2 parts of 1-phenylcyclohexane-l-carboxylic acid is converted to its potassium salt by a method similar to that described in Example 2A. A suspension of this potassium salt in 100 parts of toluene is treated with excess 'y-chloropropyl-morpholine and the mixture refluxed and stirred for hours. The hydrocarbon layer, after washing with water, is dried and distilled whereby 15.2 parts or a 92% yield of 'y-morpholinopropyl 1-pheny1cyclohexane-l-carboxylate, boiling point 202-203 C. at 2 mm., n 1.5238 is obtained.

The hydrochloride is prepared by previously described method and is crystallized from absolute alcohol to a product melting at 174-17 5 C.

EXAMPLE 4 'y-Morpholinopropyl 1-phenylcyclopropane-1-carb0xylate GHQ-CH1 O GE's-C O C CHr-Cs O C-Qi-O OH2OH2CHaN A solution of 25 parts of l-phenylcyclopropane-lcarboxylic ac d chloride m 20.5 parts of trimethylene bromphydrtn is heated on the steam bath overnight. The reaction mixture is distilled directly. The 'y-bromopropyl 1;p3henylcyclopropane-l-carboxylate boils at 151-153 C. a mm.

11.3 parts of this bromo ester is dissolved in 50 parts of dry benzene. Then there is added 7.3 parts of morpholine. The solution is refluxed and stirred several hours. Washing with water removes the precipitated morpholine hydrobromide and any unused morpholine. The benzene layer is then extracted with acid. Addition of alkali to this acidic extract regenerates the free base of the product which is dissolved in ether. The solvent is then removed and the residue distilled. The 'y-morpholinopropyl 1- phenylcyclopropane-l-carboxylate boiling at 173-175 C. at 2 mm. amounts to 8.5 parts.

The hydrochloride is prepared by previously described methods and, after crystallization from absolute alcohol is found to melt at 168-169 C.

EXAMPLE 5 The compound 'y-piperidinopropyl l-phenylcyclopropane-l-carboxylate is prepared according to the instructions given in Example 4 but substituting piperidine for the morpholine of that example.

EXAMPLE 6 EXAMPLE 7 The quaternary ammonium salt of w-morpholinohexyl l-phenylcyclohexane-l-carboxylate is prepared by dissolving 1.86 parts of the base obtained in Example 2A and 1.4 parts of methyl iodide in 50 parts of dry ether. The methiodide salt which slowly separates from the solution is collected by filtration and crystallized from absm lute alcohol. The product melts at 136 C.

Others may readily adapt the invention for use under various conditions of service, by employing one or more of the novel features disclosed or equivalents thereof. As at present advised with respect to the apparent scope of my invention, I desire to claim the following subject matter.

I claim:

1. The basic esters of the formula in which m is an integer from 2 to 5 and Rs is a lower alkylene group; their acid-addition salts and their quaternary ammonium salts.

2. The basic esters of the formula OKs-Cg:

CHPCE:

in which R2 is a lower alkylene group; their acid-addition salts and their quaternary ammonium salts.

3. The basic esters of the formula GHs-CH:

O CHI-CE:

(H) CH:

CHPCEI O OHr-O:

its acid addition salts and its quaternary ammonium salts. propane-l-carboxylate represented by the following for 5. The compound w-morpholinohexyl l-phenylcyclo mula:

hexane-l-carboxylate represented by the formula: I? GHPCH, 1| CHPCH 5 0-c-ocmomo11m o /C-OO--OH2(CHz) CHz-N 0 CHPGHI CHPCH, H2O CH2 OH2C 2 Hz H:

g its acid addition salts and its quaternary ammonium salts.

2 its acid addition salts and its quaternary ammonium salts. References Cited in the file of this Pate/l1t 6. The compound 'y-morpholinopropyl l-phenylcyclo- UNITED STATES PATENTS hexane-l-carboxylate, represented by the following formula; 2,404,588 Martln et al. July 23, 1946 0 CH CH: 2,573,015 Hafiiger et al Oct. 30, 1951 P 2,589,937 Hafliger et al Mar. 18, 1952 C( JOCH2CH2CH2N 0 CH2 CH2 OHPCQ FOREIGN PATENTS H H 240,162 Switzerland May 16, 1946 249,036 Switzerland Mar. 16, 1948 CH; 249,041 Switzerland Apr. 1, 1948 its acid addition salts and its quaternary ammonium salts. 249,042 Swltzerland P 1943 7. The compound -morpholinopropyl l-phenylcyclo- 582,535 Great Britain 20, 1946 

1. THE BASIC ESTERS OF THE FORMULA 